Method for manufacturing saddle-shaped shim coil and coil winding device

Abstract

The present application relates to the technical field of coil, especially to a saddle-shaped SHIM coil manufacturing method and a coil winding device, the coil winding device comprises a first winding plate and a second winding plate, a wire winding area is formed between the first winding plate and the second winding plate; further comprising a plurality of interval arranged winding quick release pins, the winding quick release pins horizontally penetrate the first winding plate and the second winding plate; the winding quick release pins are arranged at each vertex position of the inner layer edge of the coil layer, and the winding quick release pins are used for limiting each vertex of the inner layer of the coil layer during winding. The saddle-shaped SHIM coil manufacturing method comprises a plane SHIM coil manufacturing step, a plane SHIM coil preliminary solidification step, a saddle-shaped SHIM coil assembly step and a heating solidification step. The winding device of the present application has simple structure and high winding efficiency, when winding multiple layers of coils, the manufacturing time is short, and the manufacturing cost is low. The saddle-shaped SHIM coil manufacturing method has simple process and high manufacturing precision.

Description

Technical Field

[0001] This invention relates to the field of coil technology, and in particular to a method for manufacturing a saddle-shaped SHIM coil and a coil winding device. Background Technology

[0002] The imaging quality of a magnetic resonance imaging (MRI) system is closely related to the homogeneity of the magnetic field. This homogeneity is typically measured in parts per million (ppm) of the main magnetic field. High-field systems (such as 3T and above) require deviations to be controlled within 1–5 ppm to avoid artifacts and spectral distortion. Magnetic field homogeneity relies on the synergistic effect of gradient coils and shimming techniques: passive shimming uses shimming plates on the inner wall of the magnet to statically correct macroscopic deviations. Active shimming adjusts the current in the SHIM coil, allowing the coil to dynamically compensate for magnetic field fluctuations.

[0003] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown in the prior art, a common saddle-shaped SHIM coil includes a frame 1 and a SHIM coil 2 disposed on the frame 1. The frame 1 has a mounting groove 3 machined therein, and the SHIM coil 2 is fixedly mounted within the mounting groove 3. The SHIM coil 2 includes multiple coil layers, such as... Figure 4 The illustration shows an example of a SHIM coil 2, consisting of four coil layers nested together from the inside out, with the coil layers being rectangular. In practical applications, rectangular, pentagonal, hexagonal, or other shapes are also possible. The manufacturing methods for saddle-shaped SHIM coils include: hand winding, copper plate engraving, cutting, and stamping.

[0004] Hand winding typically involves machining winding grooves into the coil assembly and manually winding within these grooves. This method is generally suitable for helical coils or coils with a small number of turns. However, hand winding is time-consuming and unsuitable for mass production. Copper plate engraving (as described in Chinese patent CN111665466A) requires large milling machines and a fourth axis for full-body gradient coils, placing high demands on equipment and resulting in high manufacturing costs. Among cutting methods, laser cutting suffers from material oxidation, while waterjet cutting suffers from low precision and environmental unfriendliness. Stamping (as described in Chinese patent CN1536594A) requires specialized molds and is only suitable for mass-produced, standardized products.

[0005] Coil manufacturing methods, including copper plate engraving, cutting, and stamping, generally involve coil assembly preparation → coil processing → hot pressing → plate rolling → assembly, positioning, and fixing. During plate rolling, shape control is difficult, leading to deformation such as copper plate twisting. Furthermore, the coil engraving equipment has specific requirements. In subsequent assembly, the coils may become scattered, and there may be at least a 1mm kerf in the coil, resulting in low current density and a deviation from the design value.

[0006] Therefore, designing a method for manufacturing a saddle-shaped SHIM coil and a coil winding device has become a technical problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to provide a method for manufacturing a saddle-shaped SHIM coil and a coil winding device to address the above-mentioned shortcomings.

[0008] To solve the above problems, the technical solution adopted by the present invention is as follows:

[0009] A coil winding device includes a first winding plate and a second winding plate arranged side by side, with a wire winding area formed between the first winding plate and the second winding plate; it also includes a plurality of winding quick-release pins arranged at intervals, the winding quick-release pins horizontally penetrating the first winding plate and the second winding plate; the winding quick-release pins are located at each vertex position of the inner edge of the coil layer, and the winding quick-release pins are used to limit the movement of each vertex of the inner layer of the coil layer during winding.

[0010] As an improvement, a limiting step is provided on the side of the first winding plate near the second winding plate, and the limiting step has the same thickness as the coil.

[0011] As an improvement, the shape of the limiting step is the same as the inner diameter of the innermost layer of the coil.

[0012] As an improvement, the first winding plate is provided with a through-hole for wire exit, and the limiting step is provided with a wire exit groove that communicates with the wire exit hole, with the other end of the wire exit groove extending to the edge of the limiting step.

[0013] As an improvement, it also includes a cross-wire quick-release pin that runs horizontally through the first winding plate and the second winding plate. The cross-wire quick-release pin is located at the outer layer exit position or the inner layer inlet position of the coil layer and is used for guiding and positioning the wire at that position.

[0014] As an improvement, it also includes two fixing seats, each including a cylinder and a flange disposed at the end of the cylinder; the flanges of the two fixing seats are respectively fixed to the first winding plate and the second winding plate.

[0015] A method for manufacturing a saddle-shaped SHIM coil includes the following steps:

[0016] The steps for making a planar SHIM coil are as follows: based on the planar dimensions unfolded from the coil dimensions in the saddle-shaped SHIM coil, the planar SHIM coil is made using the aforementioned coil winding device.

[0017] The initial curing step of the planar SHIM coil involves briefly heat curing the planar SHIM coil to preliminarily shape it, giving the planar SHIM coil a certain degree of flexibility.

[0018] The assembly steps for the saddle-shaped SHIM coil are as follows: apply adhesive to the bottom of the mounting slot of the frame; assemble the planar SHIM coil, which has a certain degree of flexibility in the initial curing step, into the mounting slot of the frame.

[0019] The heating and curing step involves a secondary curing process for the SHIM coil assembled into the mounting slot, using a UV lamp to thoroughly cure the coil.

[0020] Preferably, when manufacturing the planar SHIM coil, a double-curing resin RA-6000 is applied to the surface of its conductor; the planar SHIM coil is then subjected to a short-term heat curing process, in which the coating is initially cured by baking in a curing oven at 70°C for 5 minutes or at 120°C for 2 minutes. The curing oven should be equipped with a heating and temperature control device.

[0021] Preferably, when fabricating the planar SHIM coil, a double-curing resin RA-6000 is applied to the surface of its conductors; in the scheme of using a UV lamp to perform secondary curing of the saddle-shaped SHIM coil, the saddle-shaped SHIM coil is irradiated with a UV lamp to achieve 600-800 mJ / cm. 2 .

[0022] The present invention adopts the above technical solution and has the following advantages compared with the prior art:

[0023] The winding device of the present invention has a simple structure and high winding efficiency. It is especially useful for winding multi-layer coils, which greatly saves the coil manufacturing time. Moreover, the labor cost of winding is low and the equipment requirements are low. It is suitable for both the research and development stage and mass production. The winding device can be used for winding superconducting coils as well as for winding room temperature coils.

[0024] The method for manufacturing the saddle-shaped SHIM coil of the present invention is simple, requires few devices, and has low manufacturing cost. Furthermore, when installing the saddle-shaped SHIM coil, the flexibility of the pre-cured planar SHIM coil is used to install the coil into the mounting groove of the coil frame, and the mounting groove is used to position the coil to ensure the accuracy of the saddle-shaped SHIM coil.

[0025] The present invention will now be described in detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0026] Figure 1 This is a three-dimensional schematic diagram of the saddle-shaped SHIM coil in the background art of this invention;

[0027] Figure 2 This is a schematic diagram of the saddle-shaped SHIM coil in the background art of this invention;

[0028] Figure 3 for Figure 2 Top view;

[0029] Figure 4 for Figure 1 A schematic diagram of the intermediate coil structure;

[0030] Figure 5 This is a three-dimensional schematic diagram of the coil winding device in Embodiment 1 of the present invention;

[0031] Figure 6 This is a reference diagram showing the usage state of the coil winding device in Embodiment 1 of the present invention;

[0032] Figure 7 for Figure 1 A schematic diagram of the structure of the first winding plate;

[0033] Figure 8 for Figure 7 Sectional view of AA;

[0034] Figure 9 for Figure 6 A schematic diagram of the structure of the first type of planar SHIM coil wound in the middle;

[0035] Figure 10 for Figure 9 Enlarged view at point B in the middle;

[0036] Figure 11 for Figure 6 A schematic diagram of the structure of the second type of planar SHIM coil wound in the middle;

[0037] Figure 12 for Figure 11 Enlarged view at point C;

[0038] Figure 13 This is a schematic diagram of the third type of planar SHIM coil in Embodiment 1 of the present invention;

[0039] Figure 14 This is a schematic diagram of the fourth planar SHIM coil in Embodiment 1 of the present invention;

[0040] Figure 15 This is a schematic diagram of the fifth planar SHIM coil in Embodiment 1 of the present invention;

[0041] Wherein: 1-frame, 2-SHIM coil, 3-mounting groove, 4-first winding plate, 5-second winding plate, 6-conductor winding area, 7-winding quick release pin, 8-limiting step, 9-outlet hole, 10-outlet groove, 11-cross-wire quick release pin, 12-fixed seat, 13-cylinder, 14-flange, 15-pin hole, 16-through hole, 17-chamfer, 18-fixing bolt, 19-winding machine, 20-winding shaft. Detailed Implementation

[0042] For ease of explanation and not for limitation, in the horizontal direction, the position on the coil winding device closest to the winding area is defined as inside, and the opposite direction is defined as outside. Along the radial direction of the coil, the position closest to the coil center is defined as inside, and the opposite direction is defined as outside.

[0043] Definitions:

[0044] Active shimming: Gradient active shimming utilizes a gradient magnetic field generated by appropriately adjusting the current in the gradient coil to dynamically correct the main magnetic field, thereby improving the uniformity of the magnetic field. It is a basic fine-tuning technique for passive shimming and is suitable for high-precision imaging requirements.

[0045] Passive shimming: Improves magnetic field uniformity by adjusting the diamagnetic material or coil current inside the magnet in one step. It is suitable for low field strength equipment or scenarios where high precision is not required.

[0046] Dual-curing adhesives: Taking dual-UV curing adhesives as an example, a dual-curing hard coating means that it is first heat-cured and then UV-cured. The coating is first briefly dried by heat to form a surface with a certain initial hardness and printability. After subsequent processing and shaping (stretching, vacuum forming, bending, etc.), it is then UV-cured to achieve the final performance hard coating.

[0047] Quick release pin: Its insertion end has a transverse opening and is equipped with a spring and elastic ball head.

[0048] Example 1

[0049] like Figures 5 to 12 As shown, a coil winding device includes a first winding plate 4 and a second winding plate 5 arranged side by side, and two fixing seats 12. Both the first winding plate 4 and the second winding plate 5 are disc-shaped, and each has a horizontally penetrating through hole 16 in its center. The fixing seat 12 includes a cylindrical body 13 and a flange 14 disposed at the end of the cylindrical body 13. The flanges 14 of the two fixing seats 12 are respectively fixed to the first winding plate 4 and the second winding plate 5. Preferably, in this embodiment, the two fixing seats 12, the first winding plate 4, and the second winding plate 5 are detachably fixedly connected by screw holes and fasteners. The fasteners are a combination of bolts and nuts.

[0050] like Figures 5 to 12 As shown, a wire winding area 6 is formed between the first winding plate 4 and the second winding plate 5, and the width of the wire winding area 6 is adapted to the width of the coil. Both the first winding plate 4 and the second winding plate 5 have a chamfer 17 on the edge closest to the wire winding area 6.

[0051] like Figure 7 and Figure 8As shown, the coil winding device also includes a plurality of spaced-apart quick-release pins 7, which horizontally penetrate the first winding plate 4 and the second winding plate 5. The quick-release pins 7 are located at various vertices of the inner edge of the coil layer, and are used to limit the movement of each vertex of the inner layer during winding. In this embodiment, the coil consists of three coil layers sequentially nested from the inside out, with each coil layer having a rectangular inner diameter.

[0052] like Figure 7 and Figure 8 As shown, a limiting step 8 is provided on the side of the first winding plate 4 near the second winding plate 5. The width of the limiting step 8 is the same as the width of the coil. The limiting step 8 is used to limit the distance between the first winding plate 4 and the second winding plate 5 to ensure that the width of the wire winding area 6 is the same as the set value.

[0053] like Figure 4 The coil shown is a three-layer coil nested sequentially from the inside out. During winding, the inner diameter of each layer of coil needs to be positioned. Positioning the innermost coil can be achieved by setting quick-release pins 7 at each vertex of the inner coil, with the wire passing over each quick-release pin 7 from the outside during winding. Alternatively, a limiting step 8 can be used to directly position the inner diameter of the innermost coil. Preferably, in this embodiment, the shape and size of the limiting step 8 are the same as the shape and size of the innermost coil, and the limiting step 8 directly positions the inner diameter of the innermost coil. During coil winding, the limiting step 8 is used to position the innermost coil. The first winding plate 4 has a through-hole 9, and the limiting step 8 has a wire outlet groove 10 communicating with the wire outlet 9, with the other end of the wire outlet groove 10 extending to the edge of the limiting step 8. A fixing bolt 18 is fixed to the outside of the first winding plate 4, located on the side of the wire outlet 9. When winding, fix the end of the wire to the fixing bolt 18.

[0054] For the positioning of the middle and outermost coil layers, quick-release pins 7 are installed at each vertex of the inner coil of each coil. The advantage of using quick-release pins 7 is that they are easy to install and remove. After the innermost coil layer is wound, the outer coil layer is wound by installing the corresponding quick-release pin 7. The quick-release pins 7 are only installed when in use, thus not affecting the winding of the inner coils, and are convenient and quick to install when needed.

[0055] like Figures 5 to 12As shown, the coil winding device also includes a quick-release pin 11 that horizontally penetrates the first winding plate 4 and the second winding plate 5. The quick-release pin 11 is located at the outer layer exit position or the inner layer inlet position of each coil layer, and is used for guiding and positioning the wire at that position. The first winding plate 4 and the second winding plate 5 are each provided with pin holes 15 corresponding to the positions of the quick-release pin 11 and the quick-release pin 7. In use, the quick-release pin 11 and the quick-release pin 7 are respectively installed in the corresponding pin holes 15. The advantage of using the quick-release pin 11 is that the external quick-release pin 11 is not installed when not in use, thus not affecting the winding of the inner wire. The quick-release pin 11 is easy to install and remove. As the winding progress of each layer of coil changes, the quick-release pin 11 can be installed in a timely manner, which does not affect the winding of the wire, and can also provide timely positioning and guidance of the wire, and the quick-release pin 11 is easy to install and remove.

[0056] like Figures 5 to 12 As shown, the method of using this coil winding device includes the following steps:

[0057] In the wire threading step, the end of the wire with the surface coating of adhesive is fixed from the inside of the first winding plate 4 through the wire outlet groove 10 and the wire outlet hole 9 to the fixing bolt 18 on the outside of the first winding plate 4. The surface coating of the wire uses a double curing agent. In this embodiment, the preferred double curing agent is Weiliang Chemical's double curing resin RA-6000.

[0058] Assembly steps of the winding device: Apply release agent to the inner layers of the first winding plate 4 and the second winding plate 5, and use the winding quick-release pin 7 to fix the first winding plate 4 and the second winding plate 5 together and align them, then follow the steps... Figure 6 The mounting base 12, the first winding plate 4, the second winding plate 5, and the mounting base 12 are fixedly connected using bolts and nuts; after all four are completely fixed, the quick-release pin 7 is removed. In the prior art, there are many types of release agents; this invention requires the selection of a release agent that has no impact on the electrical performance of the product. Preferably, in this embodiment, release agent QZ13CI is used, and it is applied evenly to the inner layers of the first winding plate 4 and the second winding plate 5 for easy demolding.

[0059] Installation and winding of the winding device: The assembled winding device is fixedly installed on the winding shaft 20 of the winding machine 19. If the quick-release pin 7 is used to position and guide the innermost coil, the quick-release pin 7 should be installed at each fixed point on the inner side of the innermost coil, and then the winding machine is turned on to wind the innermost coil. Since the limiting step 8 is used to position the inner diameter of the innermost coil in this embodiment, the winding machine is turned on directly to wind the innermost coil. After the innermost coil is finished, the cross-wire quick-release pin 11 is installed to position and guide the lead wire of this layer of coil. For winding coils with multiple coil layers, under the positioning and guidance of the cross-wire quick-release pin 11, the lead wire is guided to the starting point of the inner layer of the second coil. The quick-release pin 7 is installed at each vertex of the innermost layer of the second coil, and then the second coil is wound. The same method is repeated to wind the outer coil layers in sequence until the coil winding is finished; the wound coil is then removed from the winding device.

[0060] This embodiment uses a rectangular coil as an example for coil winding; the winding directions between each coil layer can be the same or opposite. The coil can be wound as a single strand or multiple strands wound in parallel. Figure 9 and Figure 10 The coil is wound with three layers. Figure 11 and Figure 12 Both are three-layer coils. The difference is that the winding direction of some coil layers is different. During coil winding, the winding direction of different coil layers can be achieved by controlling the winding machine to rotate forward or backward according to the designed winding direction of the coil.

[0061] This winding device can wind rectangular planar coils, as well as other polygonal planar coils. For example... Figure 13 , Figure 14 , Figure 15 As shown, by changing the position of the quick-release pin 7, this winding device can also wind polygonal coils of different shapes and layers, including but not limited to triangles, pentagons, hexagons, and octagons. Furthermore, this winding device can also produce various irregular polygonal coils simply by changing the setting position of the quick-release pin hole.

[0062] Example 2

[0063] A method for manufacturing a saddle-shaped SHIM coil includes the following steps:

[0064] Steps for fabricating a planar SHIM coil: Fabricate a planar SHIM coil based on the unfolded planar dimensions of the coil in the saddle-shaped SHIM coil. When fabricating a planar SHIM coil, it is preferable to use the winding device described in Example 1.

[0065] Preliminary curing steps for planar SHIM coils: Briefly heat-cur the planar SHIM coils to achieve initial shaping, giving them a certain degree of flexibility.

[0066] Assembly steps for the saddle-shaped SHIM coil: Apply adhesive to the bottom of the mounting groove 3 of the frame 1; assemble the planar SHIM coil, which has a certain degree of flexibility from the initial curing step, into the mounting groove 3 of the frame 1. Preferably, E-120P adhesive is used in this embodiment. The amount of adhesive used is small, and the thickness of the adhesive in the mounting groove 3 is controlled within 0.1mm, and should not be too thick. The adhesive is liquid before curing and cures relatively quickly. After applying adhesive to the bottom of the mounting groove 3 of the frame 1, fix the planar SHIM coil in the mounting groove 3 according to the set position, and tighten it with a tightening tape on the outside of the saddle-shaped SHIM coil.

[0067] Heating and curing step: The assembled saddle-shaped SHIM coil is cured a second time using a UV lamp to completely cure the coil.

[0068] It should be noted that the initial curing step of the planar SHIM coil involves a brief heat curing, while the secondary curing step utilizes a UV lamp to cure the saddle-shaped SHIM coil. Therefore, the temperature and time parameters for the brief heat curing and secondary curing need to be determined based on the material and chemical properties of the dual curing agents applied to the conductor surface during winding. Different dual curing agents will be used, and the curing method must be followed according to the manufacturer's instructions. Different manufacturers use different models, and the mixing ratios, formulations, and processes vary.

[0069] This embodiment uses Weiliang Chemical's dual-curing resin RA-6000 as an example to illustrate the dual-curing agent. The planar SHIM coil undergoes a brief heat curing process: the coating is initially cured by baking in a curing oven at 70°C for 5 minutes or 120°C for 2 minutes. The curing oven is equipped with a heating and temperature control device. After brief heat curing, the planar SHIM coil can be initially shaped, giving it a certain degree of flexibility, which facilitates subsequent installation of the planar SHIM coil into the mounting slot 3 of the frame 1.

[0070] A method for secondary curing of saddle-shaped SHIM coils using UV lamps: Irradiate the saddle-shaped SHIM coils with a UV lamp at 600–800 mJ / cm². 2 During the secondary curing of the saddle-shaped SHIM coil, the coating film of the dual-curing resin is further cured, resulting in higher hardness and better wear resistance.

[0071] In summary, the winding device of the present invention has a simple structure and high winding efficiency. Especially when used for winding multi-layer coils, it greatly saves coil manufacturing time and reduces manufacturing costs. This winding device can be used for winding both superconducting coils and room temperature coils. The method for manufacturing saddle-shaped SHIM coils has the advantages of simple process and high precision in producing saddle-shaped SHIM coils.

[0072] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A coil winding apparatus, characterized by: The coil winding device comprises a first winding plate (4) and a second winding plate (5) arranged side by side, a wire winding area (6) being formed between the first winding plate (4) and the second winding plate (5); a plurality of winding quick release pins (7) are arranged at intervals and horizontally penetrate the first winding plate (4) and the second winding plate (5); the winding quick release pins (7) are arranged at each vertex position of the inner layer of the coil layer, and are used for limiting each vertex of the inner layer of the coil layer during winding. The coil winding device further comprises a cross-wire quick release pin (11) horizontally penetrating the first winding plate (4) and the second winding plate (5), the cross-wire quick release pin (11) being arranged at the outer layer wire outlet position or the inner layer wire inlet position of the coil layer and being used for guiding and positioning the wire at the position.

2. The coil winding apparatus of claim 1, wherein: The first winding plate (4) is provided with a limiting step (8) on the side close to the second winding plate (5), and the limiting step (8) has the same thickness as the coil.

3. A coil winding apparatus as claimed in claim 2, characterised in that: The limiting step (8) has the same outer shape as the inner diameter of the innermost layer of the coil.

4. A coil winding apparatus as claimed in claim 3, characterised in that: The first winding plate (4) is provided with a wire outlet hole (9) penetrating therethrough, the limiting step (8) is provided with a wire outlet groove (10) in communication with the wire outlet hole (9), and the other end of the wire outlet groove (10) extends to the edge of the limiting step (8).

5. A coil winding apparatus as claimed in any one of claims 1 to 4, characterised in that: The coil winding device further comprises two fixing seats (12), each of which comprises a cylinder (13) and a flange plate (14) arranged at the end of the cylinder (13); the flange plates (14) of the two fixing seats (12) are fixed on the first winding plate (4) and the second winding plate (5) respectively.

6. A method of making a saddle-shaped SHIM coil, characterized by, The method comprises the following steps: A planar SHIM coil is made according to the planar size of the coil size of the saddle-shaped SHIM coil, and the coil winding device of any one of claims 1 to 5 is used to make the planar SHIM coil; The planar SHIM coil is briefly heat-cured to be preliminarily shaped, so that the planar SHIM coil has a certain flexibility; An adhesive is applied to the groove bottom of the mounting groove (3) of the skeleton (1); the planar SHIM coil with a certain flexibility in the preliminary curing step is assembled into the mounting groove (3) of the skeleton (1); The SHIM coil assembled into the mounting groove (3) is secondarily cured, and the coil is completely cured by using a UV lamp.

7. The method of making a saddle SHIM coil as defined in claim 6, wherein: When the planar SHIM coil is made, double-curing resin RA-6000 is applied to the surface layer of the wire of the planar SHIM coil; the coating is preliminarily cured by being baked in a curing oven at 70°C for 5 minutes or at 120°C for 2 minutes.

8. The method of making a saddle SHIM coil as defined in claim 6, wherein: When making the planar SHIM coil, double-cured resin RA-6000 is applied to the surface of the wire of the coil; when using the scheme of using a UV lamp to perform secondary curing on the saddle-shaped SHIM coil, the UV lamp is used to irradiate the saddle-shaped SHIM coil to 600-800 mj / cm 2 .

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